Table 1 Baseline characteristics of Chronic Renal Insufficiency Cohort (CRIC) Study participants without diabetes at baseline overall and by quartile of HOMA-IR
|  | Quartile of HOMA-IR, mmol/L * μU/mL |  | |||||
|---|---|---|---|---|---|---|---|
| Â | Overall | Quartile 1 | Quartile 2 | Quartile 3 | Quartile 4a | Quartile 4b | P-value |
(0.04–2.04) | (2.05–3.02) | (3.03–4.55) | (4.56–6.20) | (6.21–41.1) | |||
N = 1883 | N = 471 | N = 471 | N = 471 | N = 235 | N = 235 | ||
Demographic/Clinical variables | |||||||
 Age, years | 56.5 (11.9) | 54.2 (12.9) | 56.9 (11.6) | 57.7 (11.4) | 57.2 (11.6) | 57.2 (10.7) | < 0.001 |
 Male gender, % | 1011 (54.0) | 232 (49.3) | 241 (51.2) | 273 (58.0) | 136 (57.9) | 129 (54.9) | 0.04 |
 Race/ethnicity, % |  | 0.03 | |||||
 Non-Hispanic white | 939 (50.0) | 258 (54.8) | 231 (49.0) | 244 (51.8) | 104 (44.3) | 102 (43.4) |  |
 Non-Hispanic black | 724 (38.0) | 155 (32.9) | 174 (36.9) | 181 (38.4) | 103 (43.8) | 111 (47.2) | |
 Hispanic | 144 (8.0) | 38 (8.1) | 42 (8.9) | 31 (6.6) | 17 (7.2) | 16 (6.8) | |
 Hypertension, % | 1503 (80.0) | 321 (68.2) | 370 (78.6) | 397 (84.3) | 205 (87.2) | 210 (89.4) | < 0.001 |
 Current smoking, % | 258 (14.0) | 82 (17.4) | 65 (13.8) | 45 (9.6) | 36 (15.3) | 30 (12.8) | 0.01 |
 Systolic blood pressure, mmHg | 124 (20) | 122 (21) | 124 (21) | 125 (20) | 123 (19) | 124 (18) | 0.16 |
 Diastolic blood pressure, mmHg | 73 (13) | 73 (13) | 73 (13) | 73 (12) | 73 (13) | 73 (13) | 0.93 |
 Heart rate, beats/min | 67 (11) | 65 (11) | 66 (11) | 67 (11) | 67 (10) | 69 (11) | < 0.001 |
 History of cardiovascular disease, % | 452 (24) | 81 (17) | 110 (23) | 126 (27) | 64 (27) | 71 (30) | < 0.001 |
 Education, % |  |  | |||||
 Less than high school | 268 (14) | 57 (12.1) | 72 (15.3) | 74 (15.7) | 28 (11.9) | 37 (15.7) | < 0.001 |
 High school graduate | 343 (18) | 69 (14.7) | 86 (18.3) | 84 (18.5) | 52 (22.1) | 49 (20.9) | |
 Some college | 541 (29) | 115 (24.5) | 138 (29.3) | 126 (26.8) | 73 (31.1) | 89 (37.9) | |
 College graduate or higher | 730 (39) | 229 (48.7) | 175 (37.2) | 184 (39.1) | 82 (34.9) | 60 (25.5) | |
Anthropometric Variables | |||||||
 Height, m | 1.7 (0.1) | 1.7 (0.1) | 1.7 (0.1) | 1.7 (0.1) | 1.7 (0.1) | 1.7 (0.1) | 0.006 |
 Weight, kg | 87 (21.7) | 74.9 (16.5) | 81.7 (17.4) | 91.8 (20.3) | 96.9 (21.2) | 102.1 (25) | < 0.001 |
 Body mass index, kg/m2 | 30.3 (7.1) | 26.4 (4.9) | 28.8 (6.0) | 31.7 (6.2) | 33.4 (6.8) | 35.8 (8.7) | < 0.001 |
 Waist circumference, cm | 101.6 (16.3) | 91.8 (13.8) | 97.6 (13.0) | 105.1 (13.7) | 109.9 (15.2) | 114.3 (17.6) | < 0.001 |
 Fat-free mass, kg | 57.4 (14.5) | 52.2 (12.6) | 54.8 (12.8) | 60.2 (15.2) | 61.7 (14.5) | 63.0 (15.2) | < 0.001 |
Medication Use | |||||||
 Statins, % | 778 (42) | 132 (28.1) | 201 (43.3) | 223 (47.8) | 108 (46) | 114 (48.5) | < 0.001 |
 Other lipid-lowering medication, % | 855 (46) | 146 (31.1) | 219 (47.2) | 244 (52.2) | 121 (51.5) | 125 (53.2) | < 0.001 |
 ACEi or ARB use, % | 1092 (58%) | 219 (46.7) | 273 (58.8) | 287 (61.5) | 163 (69.4) | 150 (63.8) |  |
Laboratory Values | |||||||
 Fasting glucose, mmol/L | 5 (0.6) | 4.7 (0.6) | 4.9 (0.5) | 5.2 (0.6) | 5.4 (0.6) | 5.7 (0.6) | < 0.001 |
 Insulin, μg/L | 0.6 (0.4–0.9) | 0.4 (0.3–0.4) | 0.5 (0.5–0.6) | 0.8 (0.7–0.8) | 1.0 (0.9–1.1) | 1.6 (1.3–2.0) | < 0.001 |
 C-peptide, μg /L | 3.0 (2.1–4.1) | 1.8 (1.4–2.3) | 2.5 (2.0–3.1) | 3.4 (2.9–4.1) | 4.1 (3.5–4.0) | 5.8 (5.7–7.3) | < 0.001 |
 eGFR, mL/min/1.73m2 | 49 (18) | 51 (20) | 49 (18) | 48 (16) | 48 (18) | 46 (15) | 0.010 |
 24-h urine protein, g/day |  | ||||||
  < 0.10 | 838 (46) | 227 (50) | 203 (45.1) | 201 (43.7) | 99 (44.6) | 108 (48.4) | < 0.05 |
  0.10–0.49 | 543 (30) | 131 (29) | 147 (32.7) | 153 (33.3) | 59 (26.6) | 53 (23.8) | |
 0.50–1.49 | 242 (13) | 55 (12) | 66 (14.7) | 54 (11.7) | 31 (14) | 36 (16.1) | |
  ≥1.50 | 188 (10) | 43 (9) | 34 (7.6) | 52 (11.3) | 33 (14.9) | 26 (11.7) | |
 Serum albumin, g/L | 41 (4) | 40 (5) | 41 (4) | 41 (4) | 40 (4) | 41 (4) | 0.001 |
 Hemoglobin, mmol/L | 8.2 (1.1) | 8.0 (1.1) | 8.1 (1.1) | 8.2 (1.1) | 8.2 (1.1) | 8.3 (1.1) | 0.004 |
 Total cholesterol, mmol/L | 4.9 (1.1) | 5.0 (1.1) | 4.9 (1.1) | 4.8 (1.0) | 4.9 (1.0) | 4.9 (1.2) | < 0.05 |
 LDL, mmol/L | 2.8 (0.9) | 2.9 (0.9) | 2.8 (0.9) | 2.8 (0.8) | 2.8 (0.8) | 2.7 (0.9) | 0.02 |
 HDL, mmol/L | 1.3 (0.4) | 1.4 (0.5) | 1.4 (0.4) | 1.2 (0.4) | 1.1 (0.3) | 1.1 (0.3) | < 0.001 |
 Triglycerides, mmol/L | 1.4 (1.0–1.9) | 1.1 (0.8–1.6) | 1.3 (0.9–1.7) | 1.4 (1.1–2.0) | 1.6 (1.2–2.4) | 1.7 (1.2–2.8) | < 0.001 |
 Hemoglobin A1c, mmol/mol | 39 | 37 | 38 | 39 | 41 | 41 | < 0.001 |
 Uric acid, umol/L | 428.3 (113.0) | 398.5 (113.0) | 416.4 (113.0) | 434.2 (107.1) | 458 (107.1) | 475.8 (107.1) |  |
 High-sensitivity CRP, nmol/L | 22.9 (9.5–58.1) | 14.3 (7.6–34.3) | 21.0 (7.6–53.3) | 26.7 (11.4–62.9) | 32.4 (14.3–75.2) | 39.0 (14.3–81.0) | < 0.001 |
 FGF-23, relative units (RU)/mL | 121.8 (84.0–199.2) | 111.9 (76.2–189.9) | 117.0 (80.6–181.2) | 128.3 (87.3–206.6) | 130.4 (91.3–222.0) | 136.0 (91.0–234.4) | < 0.001 |